In a peer to peer system it is often desirable to minimize the duration and amount of power required to transmit peer to peer signals, e.g., peer discovery signals. When a peer to peer system shares communications resources with a wide area network (WAN) or the peer to peer frequency band is close to the frequency band being used by the wide area network, peer to peer discovery signals can create interference to the access nodes, e.g., base stations in the WAN.
In a WAN all communication to/from a mobile node normally goes through an infrastructure element, e.g., base station via uplink/downlink channels between mobiles and base station. Thus, in a WAN, communications with a network element or between mobile nodes normally passes through a base station.
In the case that two communicating mobiles are in the vicinity of each other, direct peer to peer communication without going through a base station can reduce the base station load. However, in such systems, which support WAN and peer to peer communications it can be important not only to minimize the amount of interference to the base station from peer to peer communication, including the transmission of discovery signals, but it can also be important to minimize the amount of transmission power consumed by mobile stations. For example, it may be desirable to minimize the amount of power used for performing peer to peer communications since mobile devices normally are limited in the amount of time they can communicate by the amount of battery power available.
In view of the above discussion, it should be appreciated that there is a need for methods and apparatus that allow peer to peer devices within range of a base station to send and receive peer discovery information in a manner which limits the amount of interference to WAN communications and/or uses available wireless terminal power efficiently.